I was wondering if its safe to attach and ND or UV filter to the stock lens and then stack a wide or tele lens on top of that? Or is the weight of the add-on lens not good for the filter threads. they are pretty heavy glass.

Thanks

Yes. You can do that. But it is not a good idea, and not just because of weight. Putting filters between a conversion lens and the primary lens can cause reflections internal to the conversion lens that reduce contrast and create ghosts and other undesirable effects. It is best to put your filters in front of the conversion lens.

Thanks Guy, I appreciate that.